Fault Creep, Borehole Strain, and Tiltmeter Monitoring Measurements

The USGS maintains a variety of fault and volcano monitoring
sites around the western United States. Instruments at these sites include
strainmeters, tiltmeters and creepmeters, as well as other environmental
parameters such as temperature and barometric pressure.

The data are collected and monitored to help understand how, when, and why
large earthquakes, fault slip and volcanic activity occur. The measurements
provide a near real-time record of the related crustal deformation before,
during and after events. The goal is to better understand these natural
processes, and use these data to reduce the earthquake and volcanic hazards
associated with them.

This web site provides data plots and
data downloads for many instruments that are
concentrated in areas where large earthquakes are likely to occur in
California and areas of known volcanic activity. In
particular, the USGS has concentrated instrumentation efforts in the San
Francisco Bay Area, near San Juan Bautista and Parkfield, and the Long Valley,
CA and Southern California regions.

The plots and data on this site are generated
automatically and are not reviewed. They should not be used for engineering,
legal, or any other critical applications.